Dysfunction and disorder of nails caused by e.g. onychomycosis is an increasingly common and recalcitrant fungal nail infection world-wide.
A dysfunction or disorder of nails is often induced or caused by fungal infections of the nails and/or nail beds. Particularly in the later stages of such an infection said dysfunctions or disorders are difficult to treat. Said dysfunctions or disorders of nails comprise, for example onychomycosis, onychocryptosis, and onychodystrophy. Bacteria like staphylococci or yeast may cause the bacterial infection paronychia, a superficial infection of the nail wall.
The current treatment of onychomycosis generally falls into three categories:    a) systemic administration of antifungals,    b) surgical removal of all or part of the nail followed by topical treatment of the exposed tissue, or    c) topical application of conventional creams, lotions, gels or solutions on the infected nail, frequently including the use of bandages to keep these dosage forms in place on the nails.
Systemic, generally oral administration of an antifungal agent for the treatment of onychomycosis requires a long term treatment (6 months and longer) and the administration of high doses (200-400 mg per day) of an antifungal agent. Surgical removal of the whole nail or parts thereof is painful, requires bandaging of the whole toe or finger and causes undesirable cosmetic appearance. Topical dosage forms such as gels, creams, solutions, lotions, lacquers etc. have the drawback that the pharmaceutically active agent is not in sufficient intimate contact with the nail.
Plasters for the treatment of onychomycosis are known. For instance, WO-A-99/40955 discloses a pressure sensitive adhesive matrix patch for the treatment of onychomycosis. This device for treating fungal infections of toenails and fingernails is made up of an occlusive backing layer and a pressure-sensitive adhesive matrix layer wherein an effective amount of an antifungal agent is uniformly dispersed, optionally with a chemical enhancer. The matrix layer has a first surface adhering to the backing layer and a second surface adapted to be in diffusional contact with the infected nail and surrounding skin area.
A method for treating onychomycosis is described in U.S. Pat. No. 5,464,610. Within said method a plaster preparation is used comprising salicylic acid or a salt, ester or mixture thereof. Said plaster preparation is attached to a carries and the salicylic acid is present in the plaster preparation in an amount ranging from 10 to 80% by weight of the preparation.
Nail evulsion compositions and methods for evulsing nails and treating nail and nail bed infections are disclosed in U.S. Pat. No. 5,993,790. Claimed is a topical nail enamel composition comprising water-based nail lacquer, a preservative, urea, and a natural additive. Said nail enamel composition is suitable for the treatment of fungal, yeast, and bacterial infections of the nails and the nail beds.
U.S. Pat. No. 5,753,256 discloses a plaster for the treatment of nail mycoses which consists of a flexible covering film, a layer of an acrylate polymer matrix, inseparably linked to said covering film, and comprises an active compound selected form miconazole, econazole, isoconazole, tioconazole, terconazole, oxiconazole, ketoconazole, itraconazole, tolciclate, sulbentine, haloprogin, griseofulvin, cyclopirox, terbinafin, and salts of these compounds. The use of sertaconazole as antifungal agent is not mentioned.
It is object of the present invention to provide a plaster for prophylaxis and/or treatment of onychomycosis and of other dysfunctions or disorders of nails.
This object is solved by the plaster of the independent claims, the method of treatment claims, and the use of said plaster. Further advantageous features, aspects and details of the invention are evident from the dependent claims, the description, and the examples of the present application.